1. Field of the Invention
The present invention relates to an in-vehicle communication system that includes a gateway for relaying communication between an external apparatus and an in-vehicle LAN.
2. Description of Related Art
Conventionally, for use in an in-vehicle gateway that transfers data, a technology (data filtering technology) is known that determines whether to transfer data according to the contents of data or the state of the vehicle (for example, Japanese Patent Application Publication No. 2002-16614 (JP 2002-16614 A)).
Japanese Patent Application Publication No. 2002-16614 (JP 2002-16614 A)) describes that unauthorized access is prevented by not allowing incomplete data or illegal data from passing through the gateway. Japanese Patent Application Publication No. 2002-16614 (JP 2002-16614 A)) also describes that the amount of data is limited according to the vehicle state (for example, power state, traveling state, or parking state, etc.).
However, when data is filtered according to the contents of data as described in Japanese Patent Application Publication No. 2002-16614 (JP 2002-16614 A)), legal data and illegal data cannot be distinguished depending upon the data that is transferred, sometimes with the possibility that unauthorized access by a malicious third party is permitted. In addition, the primary purpose of limiting the amount of data according to the vehicle state, as described in Japanese Patent Application Publication No. 2002-16614 (JP 2002-16614 A)), is to reserve the traffic. This means that there is room for improvement from the viewpoint of preventing unauthorized access by a malicious third party.